comparing data types after using scanf in C

[PrisonLove]

Hey,

So the goal is to read input from the user using scanf(), which is easy enough, but I want to make certain that the user entered an integer, how would I do that? I'm making an integer linked list so the user needs to enter an int and I need to make sure that if he/she doesn't, they will be prompted again and again until they do.

This is a snippet of my code:

int userVal;
:
:
printf("Please enter an integer value: ");
scanf("%d", &userVal);
printf("\n");
curLoc = node_addAfter(curLoc, userVal);

Any thoughts?

Thanks!

 

[The Helper]

check each character with isdigit() macro in ctypes.h

source

Additional might be useful info

Google It

 

[PrisonLove]

Okay then one more question, how would I iterate through each character in an integer to check if it is a digit?

 

[GetTriggerUnit-]

Basicly, bit shifting.
1 int = 4 byte -> 4 char

int myValue = 5;
char bytes[4];

bytes[0] = myValue >> 24;
bytes[1] = myValue >> 16;
bytes[2] = myValue >> 8;
bytes[3] = (char) myValue;

// bytes is not equal to the 4 chars of the int.

Might want to use & (AND) 0xFF for unsigned variables.

 

[The Helper]

If you want you could make your input a string and use string functions on it

You can find the length of the string using Len (or length or whatever) and loop through each character
if each character is a digit convert the string to an integer at the end then use it to set the cursor location

 

[Sgqvur]

include <stdio.h> // fgets
include <stdlib.h> // for atoi?

char input[INPUT_SIZE]
int inputi

do

    inputi = atoi(fgets(input, input.size, stdin))
    mylist.addAfter(somenode, inputi)

while inputi != MY_STOP_CONST

// Okay then one more question, how would I iterate through each character in an integer(why integer?) to check if it is a digit? 
for int i = 0, i < input.size, i++
    char ch = input<i>

    if &#039;0&#039; &lt;= ch &lt;= &#039;9&#039;
        // ch is digit
</i>